Locomotive-boiler



UNITED STATES PATENT ()FFIQE.

JOHN E. \VOOTIEN, OF READING, AND J. SNOWVDEN BELL, OF ALLEGHENY, 'ASSIGNORS TO THE \VHARTON RAILROAD SWITCH COMPANY, OF PHILA- DELPHIA, PENNSYLVANIA.

LOCOMO'TlVE-BOILER.

SPECIFICATION forming part of Letters Patent No. 361,661, dated April 19, 1887.

Application filed February 17. 1887. Serial No, 227,900. (No model.)

To all whom, it may concern.-

Be it knownthat we, JOHN E. \VOO'ITEN, of Reading, in the county of Berks and State of Pennsylvania, and J. SNOWDEN BELL, of Allegheny, in the county of Allegheny and State aforesaid, have jointly invented certain new and useful Improvements in Locomotive-Boilers, of which improvements the following is a specification.

Our improvements relate tolocomotive-boilers of the wide fire-box type, which is exemplified in the Letters Patent of John E. \Vootten, No. 192,725, July 3, 1877; No. 254,581, March 7, 1882; No. 291,120, January 1, 1884; No.352,215, November 9, 1886, and No. 354,370, December 14, 1886, and their objects are to afford an increased area of firebox-heating surface without material reduction of grate area, to reduce the width of crown-sheets, and consequently the liability to leakage by reason of expansion and contraction, and to improve the performance of the boiler in the consumption particularly of inferior grades of fuel of bituminous character.

T 0 these ends our invention, generally stated, consists in the combination,with a locomotiveboiler having a fire-box extended laterally beyond its shell, of acentral water leg or chamber forming two separate furnaces, and a firebridge located in each of said furnaces and separating the fuel-'space'thereof from a combustion-space at its front end.

The improvements claimed are hereinafter fully set forth.

In the accompanying drawings, Figure '1 is a vertical longitudinal central section through a locomotive-boiler embodying our invention; Fig. 2, a horizontal section through the firebox at the line a: a; of Fig. 1; Fig. 3, a transverse section through the same at the line y y of Fig. 1; Fig. 4, a horizontal section illustrating the application of water-walls in lieu of brick bridges; Fig. 5, a vertical longitudinal central section through a fire-box, illustrating a modification of our invention; and Fig; 6, a horizontal section through the same at the line 2 z of Fig. 5.

The boiler in which our invention is shown as applied accords in its general leading features with those of the YVootten type, heretofore and. at present employed in various classes of railroad service, the features of difference therefrom which constitute our present invention being hereinafter specified in detail. A series of fire-tubes, 2, extends in the ordinarymanner through the cylindrical waist or barrel 1 from the smoke-box3 to the fire-box 4, which is so located relatively as to the waist as to be, when placed in position upon the frame of the engine, entirely above the driving-wheels, its bottom being either substantially in the same horizontal plane as the bottom line of the waist or entirely above the same, as preferred. The fire-box is also, as in previous constructions of the wide firebox type, extended laterally beyond the waist and the planes of the driving-wheels to any desired extent within the maximum width admissible for passage over the road.

Boilers of this type as heretofore constructed have been provided with a single furnace, the dimensions and grate area of which are materially greater than those obtainable under any other construction which has heretofore been applied in practice or known in the art, so far as our knowledge and information extend. A combustion-chamber in the waist of the 'boiler, having a bridge-wall at its end nearest the fire-box, has also been employed almost universally in practice; but means for enabling the same to be dispensed with when desired have been provided and are set forth in Letters Patent Nos.352,215 and 354,370,aforesaid. In many instances, especially where the fuel employed is of low grade, free burning, and contains a considerable percentage of hydrocarbons tending to evolve smoke, the use of two furnaces has been deemed desirable, and our present invention is designed to render the same practicable without undue expense or complication of construction or incidental curtailment of grate area to any objectionable degree. The appliances which we provide to this end, and which form the subject-matter of our invention, are of the following construction:

A central water leg or chamber, 12, which is open at its top and at its rear end and closed at bottom by a water-space bar,22, divides the firebox 4 into two separate and independent furnaces, 13 14, each of which is provided with a r fire-box 4. The rear end of the water-leg 12 is open to and communicates directly with the rear water-space of the fire-box, and its front sheet is rearwardly inclined from its connection at top with the side sheets of the leg and the tubesheet 5 for a portion or for the whole of its length, so as to provide an open space, 16, in and entirely across the fire-boxin advance of the water-leg, which space communicates in rear with the furnaces 13 14, and in front with the series of fire-tubes, and serves as a combustion-chamber, within which the combustion of the gases evolved from the fuel in the furnaces is perfected prior to their passage into and through the tubes. The watervleg 12 is preferably connected at or near its bottom with the waist of the boiler by a circulating-pipe, 18, throughwhich a current of the colder water from the lower port-ion of the waist is maintained therefrom to the water-leg.

While we have shown a water leg or chamber as constituting the division-wall between the furnaces, and consider such to be the pref erable construction, this function may, if desired, be performed by a wall formed of firebrick, which we here specify as a mechanical equivalent within the scope of our invention.

The combustion-space 16 is separated from the fuel-spaces of the furnaces 13 14 by firebridges 17, composed of fire-brick and extending from ajunction one with the other at the front of the water-leg 12 to thetube-sheet 5 at points exterior to the line of the outer rows of tubes 2, so as to prevent the ingress of fuel thereto, while permitting the free passage of the escaping gases over their tops into the combustion-chamber 16 and thence to the tubes. In lieu of two fire-bridges each inclin'ed at an angle to the tube-sheet from a central meeting-point, as shown, a single bridge extending entirely across the fire-box may be employed, if preferred. In the latter case the function of the bridge as a boundary to a combustion space or chamber common to both furnaces is similarly performed, but a larger reduction of grate area is involved. The fire-bridges 17 are supported upon a plate, 9, which extends from the fire-bridges to the tube-sheet 5, upon or close to the top of the forward portion of the grates, said plate closing the bottom of the combustion-chamber and preventing the passage of cold air from the ash-pan to the tubes, similarly to the firebridge-supporting plate of Patent No. 352, 215,

before recited.

The plate 9 may be protected from the destructive action of the heat by a cover, 19, of fire-brick or other refractory material, fitting over its upper surface, and is supported by lugs or bearers secured to the firebox-sheets, as in Patent No. 352,215.

Fig. rtshows a construction in which waterwalls 20, communicating at their ends with the central water-leg, 12, and the front waterspace of the fire-box, respectively, are substituted for the fire-bridges 17 as division-walls between the combustion space or chamber 16 and the fuel-spaces of the furnaces 13 14, said water-walls in this regard performing the office of and being mechanical equivalents for the fire-bridges 17 and serving, further, to provide an increased area of evaporative surface exposed to the direct action of the fire.

It will be seen that in the application of our improvements a large increase of fire-boxheating surface is attained in the side sheets of the central water-leg without a corresponding or proportionate reduction of grate area, and such reduction of grate areaasis involved in the closure of the bottom of the combustionchamber is admissible, by reason of the large capacity of the fire-box and the facility of compensating therefor underconditions where it may be necessary or advisable so to do, by a comparatively slight increase in the length of the fire-box. The inclination of the forward end of the central water-leg facilitates the evolution of steam from the water therein, and circulation of water is effectively maintained by the lower circulation-pipe connecting the water-leg with the waist of the boiler. The substitution of two narrow crown-sheets for a single one of double their width affords corresponding exemption from leakage due to the effects of expansion and contraction, and the communication of the two independent furnaces with the tubes through a combustionchamber in the fire-box common to both furnaces enables alternate firing to be practiced with advantageous results in the prevention of smoke in the use of various low-grade bituminous fuels, the employment of which in ordinary fire-boxes is, where at all practicable,

attended with much objection from the large amount of smoke and dirt discharged from the stack.

Figs. 5 and 6 illustrate a modification of our improvements, in which the central waterleg, 12, extends continuously throughout the length of the fire-box, and is connected at its front end to the flue-sheet 5 for its fullheight, its front end being open throughout and at fording direct communication between the water-space in the'leg and the waist of the boiler. Each of the furnaces 13 14 is in such case provided with a combustion space or chamber, 16, independent of that of the other furnace, such chamber being separated from the fuel-space of the furnace by a fire-bridge, 17, which extends from the central water-leg to the side too IIO

water-space of the furnace, and is supported upon a plate, 9, closing the bottom of the combustion-chamber, as in the construction be-- fore described.

We disclaim, broadly, a combustion-chain ber closed at bottom and located within a locomotive fire-box, as also a fire-bridge dividing a fire-box into a fuel-space and a combustion-space, the same being set forth in Letters Patent No. 352,315, before referred to.

We claim as ourinvention, and desire to secure by Letters Patent- 1. The combination, in a locomotive-boiler, of a laterally-extended fire-box, a central water leg or chamber forming two separate furnaces therein, and a fire-bridge located in each of said furnaces and separating the fuel-space thereof from a combustion space or chamber at its front end, which communicates with the tubes of the boiler, substantially as set forth.

2. The combination, in a locomotive-boiler, of a laterally-extended firebox, a central water leg or chamber forming two separate furnaces therein and having its front end sepa rated from the tube-sheet,so as to afford aclear opening across the fire-box, and a fire-bridge located atthe front end of each of the furnaces and separating the fuel-spaces thereof from a common combustion space or chamber located at the front of the central water-leg and communicating with the tubes of the boiler, substantially as set-forth.

8. The combination, in a locomotive-boiler, of a laterally-extended fire-box, a central water leg or chamber forming two separate furnaces therein and having its front end separated from the tube sheet, so as to afford a clear opening across the fire-box, and a fire bridge or bridges extending from the central waterleg to the tube-sheet at points onthe latter exterior to the outer rows of tubes,'sulostantially as set forth.

4. The combination, in a locomotive-boiler,

of a laterally-extended fire-box, a central water leg or chamber forming two separate furnaces therein and having its front end rearwardly-inclined from its top, and a fire bridge or bridges extending from the central waterleg to the fire-box shell, substantially as set forth.

5. The combination, in a locomotive-boiler, of alaterally-extended fire-box, a central water leg or chamber forming two separate furnaces therein and having its front end separated from the tube-sheet, so as to afford a clear opening across the firebox, a circulating-pipe connecting the lower portion of the water-leg with the waist of the boiler, and a fire-bridge located at the front end'of the fuel-space of each of the furnaces, substantially as set forth. 6. The combination, in alocomotive-boiler, of a laterally-extended fire-box, a central water leg or chamber forming two separate furnaces therein, a fire-bridge located at the front end of each of said furnaces and separating. the fuel-spaces thereof from a common combustion space or chamber, a plate supporting said fire-bridge, and closing the bottom of the chamber, and a cover or facing of refractory material covering, the upper surface of the supporting-plate, substantially as set forth. JOHN E. WOOTTEN.

J. SNOWDEN BELL. Witnesses as to J. E. Wootten:

AUG sTUs W. HOFF, W. F. Woo'rTEN. \Vitnesses as to J. Snowden Bell:

R. H. WHITTLESEY, F. E. GAITHER. 

